Triatoma melanica Neiva and Lent, 1941

Costa, Jane, Argolo, Ana Maria & Felix, Márcio, 2006, Redescription of Triatoma melanica Neiva & Lent, 1941, new status (Hemiptera: Reduviidae: Triatominae), Zootaxa 1385, pp. 47-52 : 48-51

Triatoma melanica Neiva and Lent, 1941 , stat. nov.

( Fig. 1 )

Length of male 20.3–24.0 mm, of female 21.0–24.0 mm; width of pronotum (posterior lobe) of male 3.5–4.7 mm, of female 3.5–5.0 mm; width of abdomen of male 6.7–8.3 mm, of female 7.0– 10.5 mm. All measurements are in Table 1 .

Overall color yellowish-brown.

Head black. Head twice as long as wide across eyes (1:0.40–0.65), length often equal to length of pronotum (1:0.65:1.00). Anteocular region five times as long as postocular region (1:0.20), the latter with sides slightly rounded. Clypeus distinctly but not abruptly widened behind middle. Genae tapering distally but apices narrowly rounded, not pointed, slightly projecting beyond apex of clypeus. Jugae widely rounded apically. Eyes in lateral view approaching but not attaining level of under surface and remote from level of upper surface of head. Ratio width of eye to synthlipsis 1:1.40–2.35. Antenniferous tubercles inserted slightly posterior to middle of anteocular region. First antennal segment attaining level of apex of clypeus; second segment subcylindrical, beset with declivous setae shorter than diameter of segment. Ratio of antennal segments 1:4.2–5.8:2.2–3.8:2.0–2.2. Rostrum thick, as dark as head capsule, with medium-sized hairs on first and on underside of second segment, and with long and very numerous hairs on upper surface of second and on entire third segment; hairs especially dense dorsally at junction of second and third segments. First rostral segment reaching level of apex of antenniferous tubercles, second segment to level of middle of eyes. Ratio of rostral segments 1:1.5–3.8:0.6–1.6. Neck dark, with a pair of light-colored spots laterally. Pronotum very sparsely granulose, overall color dark. Anterior lobe with discal tubercles yellow. Posterior lobe with pair of conspicuous trapezoidal yellowish marks, these not extending to anterior lobe. Anterior lobe with very low discal tubercles; lateral tubercles absent. Posterior lobe coarsely wrinkled. Submedian carinae evanescent on posterior fourth of hind lobe. Humeral angles rounded, slightly angular. Scutellum black, posterior process with yellow apex; scutellum coarsely wrinkled, with distinct central depression; posterior process of scutellum as long as main body of scutellum, subcylindrical, but slightly compressed laterally, apex slightly elevated, rounded. Hemelytra extending to base or apex of seventh urotergite; corium light yellow, discal cells entirely or almost entirely dark brown; clavus entirely dark; membrane fumose, light yellowish brown, as light as light-colored areas of corium; veins of membrane brown; lumen of cells each with more or less extensive, irregularly shaped sooty spot extending over central portion. Legs dark, with light yellow markings on trochanters; femora entirely dark; apices of tibiae slightly yellow. Legs slender, fore femur 6–7 longer than wide. Fore and mid femora prominent below subapically or with 1–2 weak denticles.

Males with spongy fossula on fore tibia; fossula absent in females. Abdomen slightly flattened below, delicately striate transversally, sparsely setose. Spiracles adjoining connexival suture. Venter black; spiracles enclosed in minute yellow area. Connexival segments on disc with yellow rectangular spot; wide black spot enclosing intersegmental sutures; yellow and black spots of about identical size, occupying entire width of segments. Abdomen of female very wide, lateral portions of urotergites exposed.

Male genitalia. As described by Lent and Jurberg (1978). [According to Costa et al. (1997a) the variation in male genital structures of T. brasiliensis is not correlated with the different chromatic forms. Therefore, these structures are not useful to distinguish T. melanica .]

Material examined. Brazil, Minas Gerais State: Espinosa (14°55`34``S, 42°49`09``W), 10 males and 10 females ( CEIOC); Porteirinha (15°44`36``S, 43°01`42``W), 5 males and 2 females ( CEIOC). The type of T. brasiliensis melanica is lost.

Diagnosis. Triatoma melanica can be distinguished from the other members of the T. brasiliensis species complex by the following combination of features: (1) pronotum with pair of conspicuous trapezoidal yellowish marks on posterior lobe, these marks not extending to anterior lobe; (2) hemelytra with discal cells entirely or almost entirely dark brown; and (3) males with a spongy fossula only on the fore tibia.

Figures

FIGURE 1. Triatoma melanica stat. nov., male, from Espinosa (Minas Gerais State, Brazil), dorsal habitus.

Tables

TABLE 1. Measurements (in mm) of Triatoma melanica stat. nov. based on 10 males and 10 females from Espinosa, Minas Gerais State, Brazil.

Gender	Male				Female
Variables	min. max.	X	S2	S	min. max. X	S2	S
Total length	20.3 24.0	21.75	0.011	0.103	21.0 24.0 22.70	0.009	0.095
Length of head	3.5 5.3	4.18	0.003	0.056	3.5 4.8 4.25	0.003	0.057
Width of head	1.0 1.2	1.07	0.000	0.009	1.0 1.3 1.18	0.000	0.012
Synthlipsis	0.8 1.2	1.03	0.000	0.012	1.0 1.3 1.18	0.000	0.009
Width of eyes	0.5 0.7	0.56	0.000	0.007	0.5 0.7 0.57	0.000	0.007
Length of 1st antennal segment	0.8 1.0	0.90	0.000	0.008	0.8 0.8 0.83	0.000	0.000
Length of 2nd antennal segment	3.2 4.8	4.14	0.002	0.045	3.5 3.7 3.58	0.000	0.012
Length of 3rd antennal segment	1.8 3.2	2.53	0.002	0.048	1.8 2.5 2.17	0.002	0.047
Length of 4th antennal segment	1.2 2.2	1.11	0.007	0.087	2.2 2.7 2.42	0.001	0.035
Length of 1st rostral segment	0.8 1.3	1.11	0.000	0.013	0.8 1.5 1.18	0.000	0.018
Length of 2nd rostral segment	1.5 3.2	2.38	0.003	0.056	1.5 3.2 2.38	0.002	0.051
Length of 3rd rostral segment	0.8 1.8	1.18	0.001	0.031	0.8 1.0 0.90	0.000	0.009
Length of pronotum	3.2 4.3	3.54	0.001	0.033	3.0 3.7 3.33	0.000	0.021
Anterior width of pronotum	1.8 3.0	2.56	0.002	0.046	1.8 3.2 2.95	0.002	0.041
Posterior width of pronotum	3.5 4.7	4.25	0.002	0.048	3.5 5.0 4.65	0.002	0.045
Width of abdomen	6.7 8.3	7.39	0.004	0.062	7.0 10.5 8.52	0.012	0.110